Example for Configuring Prefix-based BGP ORF
Prefix-based BGP ORF is used to implement on-demand BGP route advertisement.
Networking Requirements
On the network shown in Figure 1, Devices A and B are in AS 100. Devices C, D, and E are in AS 200. Device A requires Device C to send only routing information matching the import policy of Device A, but Device C does not want to maintain a separate export policy for Device A. In this case, prefix-based BGP ORF can be configured.
Configuration Roadmap
The configuration roadmap is as follows:
Establish an EBGP peer relationship between Devices A and C, and establish IBGP peer relationships between Devices A and B, between Devices C and D, and between Devices C and E.
Configure a prefix-based import policy on Device A, and enable prefix-based BGP ORF on Devices A and C.
Data Preparation
To complete the configuration, you need the following data:
Router IDs 1.1.1.1 and 2.2.2.2 and AS number 100 of Devices A and B respectively
Router IDs 3.3.3.3, 4.4.4.4, and 5.5.5.5 and AS number 200 of Devices C, D, and E respectively
Procedure
- Configure an IP address for each interface.
Configure an IP address for each interface, as shown in Figure 1. For details on configuration procedures, see corresponding configuration files.
- Establish BGP peer relationships.
# Configure Device A.
[~DeviceA] bgp 100 [*DeviceA-bgp] router-id 1.1.1.1 [*DeviceA-bgp] peer 10.2.1.1 as-number 100 [*DeviceA-bgp] peer 10.1.1.2 as-number 200 [*DeviceA-bgp] ipv4-family unicast [*DeviceA-bgp-af-ipv4] import-route direct [*DeviceA-bgp-af-ipv4] quit [*DeviceA-bgp] commit [~DeviceA-bgp] quit
# Configure Device B.
[~DeviceB] bgp 100 [*DeviceB-bgp] router-id 2.2.2.2 [*DeviceB-bgp] peer 10.2.1.2 as-number 100 [*DeviceB-bgp] commit [~DeviceB-bgp] quit
# Configure Device C.
[~DeviceC] bgp 200 [*DeviceC-bgp] router-id 3.3.3.3 [*DeviceC-bgp] peer 10.1.1.1 as-number 100 [*DeviceC-bgp] peer 10.3.1.1 as-number 200 [*DeviceC-bgp] peer 10.4.1.1 as-number 200 [*DeviceC-bgp] ipv4-family unicast [*DeviceC-bgp-af-ipv4] import-route direct [*DeviceC-bgp-af-ipv4] quit [*DeviceC-bgp] commit [~DeviceC-bgp] quit
# Configure Device D.
[~DeviceD] bgp 200 [*DeviceD-bgp] router-id 4.4.4.4 [*DeviceD-bgp] peer 10.3.1.2 as-number 200 [*DeviceD-bgp] commit [~DeviceD-bgp] quit
# Configure Device E.
[~DeviceE] bgp 200 [*DeviceE-bgp] router-id 5.5.5.5 [*DeviceE-bgp] peer 10.4.1.2 as-number 200 [*DeviceE-bgp] commit [~DeviceE-bgp] quit
- Configure a prefix-based import policy on Device A.
# Configure Device A.
[~DeviceA] ip ip-prefix 1 index 10 permit 10.3.1.0 24 less-equal 32 [*DeviceA] bgp 100 [*DeviceA-bgp] peer 10.1.1.2 ip-prefix 1 import [*DeviceA-bgp] commit [~DeviceA-bgp] quit
# View routing information sent by Device C.
[~DeviceC] display bgp routing-table peer 10.1.1.1 advertised-routes BGP Local router ID is 3.3.3.3 Status codes: * - valid, > - best, d - damped, x - best external, a - add path, h - history, i - internal, s - suppressed, S - Stale Origin : i - IGP, e - EGP, ? - incomplete RPKI validation codes: V - valid, I - invalid, N - not-found Total Number of Routes: 7 Network NextHop MED LocPrf PrefVal Path/Ogn *> 3.3.3.3/32 10.1.1.2 0 0 200? *> 10.1.1.0/30 10.1.1.2 0 0 200? *> 10.1.1.1/32 10.1.1.2 0 0 200? *> 10.3.1.0/30 10.1.1.2 0 0 200? *> 10.3.1.1/32 10.1.1.2 0 0 200? *> 10.4.1.0/30 10.1.1.2 0 0 200? *> 10.4.1.1/32 10.1.1.2 0 0 200?
# View routing information accepted by Device A.
[~DeviceA] display bgp routing-table peer 10.1.1.2 received-routes BGP Local router ID is 1.1.1.1 Status codes: * - valid, > - best, d - damped, x - best external, a - add path, h - history, i - internal, s - suppressed, S - Stale Origin : i - IGP, e - EGP, ? - incomplete RPKI validation codes: V - valid, I - invalid, N - not-found Total Number of Routes: 2 Network NextHop MED LocPrf PrefVal Path/Ogn *> 10.3.1.0/30 10.1.1.2 0 0 200? *> 10.3.1.1/32 10.1.1.2 0 0 200?
When prefix-based BGP ORF is not enabled, Device C sends seven routes, but Device A accepts only two routes because Device A applies the prefix-based import policy to the seven routes.
- Enable prefix-based BGP ORF.
# Configure Device A.
[~DeviceA] bgp 100 [*DeviceA-bgp] peer 10.1.1.2 capability-advertise orf ip-prefix both [*DeviceA-bgp] commit [~DeviceA-bgp] quit
# Configure Device C.
[~DeviceC] bgp 200 [*DeviceC-bgp] peer 10.1.1.1 capability-advertise orf ip-prefix both [*DeviceC-bgp] commit [~DeviceC-bgp] quit
- Verify the configuration.
# View prefix-based BGP ORF negotiation information on Device A.
[~DeviceA] display bgp peer 10.1.1.2 verbose BGP Peer is 10.1.1.2, remote AS 200 Type: EBGP link BGP version 4, Remote router ID 3.3.3.3 Update-group ID: 1 BGP current state: Established, Up for 00h00m01s BGP current event: RecvRouteRefresh BGP last state: OpenConfirm BGP Peer Up count: 2 Received total routes: 0 Received active routes total: 0 Advertised total routes: 5 Port: Local - 179 Remote - 54545 Configured: Active Hold Time: 180 sec Keepalive Time:60 sec Received : Active Hold Time: 180 sec Negotiated: Active Hold Time: 180 sec Keepalive Time:60 sec Peer optional capabilities: Peer supports bgp multi-protocol extension Peer supports bgp route refresh capability Peer supports bgp outbound route filter capability Support Address-Prefix: IPv4-UNC address-family, rfc-compatible, both Peer supports bgp 4-byte-as capability Address family IPv4 Unicast: advertised and received Received: Total 3 messages Update messages 1 Open messages 1 KeepAlive messages 1 Notification messages 0 Refresh messages 1 Sent: Total 9 messages Update messages 5 Open messages 2 KeepAlive messages 1 Notification messages 0 Refresh messages 1 Authentication type configured: None Last keepalive received: 2012-03-06 19:17:37 UTC-8:00 Last keepalive sent : 2012-03-06 19:17:37 UTC-8:00 Last update received: 2012-03-06 19:17:43 UTC-8:00 Last update sent : 2012-03-06 19:17:37 UTC-8:00 Minimum route advertisement interval is 30 seconds Optional capabilities: Route refresh capability has been enabled Outbound route filter capability has been enabled Enable Address-Prefix: IPv4-UNC address-family, rfc-compatible, both 4-byte-as capability has been enabled Multi-hop ebgp has been enabled Peer Preferred Value: 0 Routing policy configured: No import update filter list No export update filter list Import prefix list is: 1 No export prefix list No import route policy No export route policy No import distribute policy No export distribute policy
# View routing information sent by Device C.
[~DeviceC] display bgp routing-table peer 10.1.1.1 advertised-routes BGP Local router ID is 3.3.3.3 Status codes: * - valid, > - best, d - damped, x - best external, a - add path, h - history, i - internal, s - suppressed, S - Stale Origin : i - IGP, e - EGP, ? - incomplete RPKI validation codes: V - valid, I - invalid, N - not-found Total Number of Routes: 2 Network NextHop MED LocPrf PrefVal Path/Ogn *> 10.3.1.0/30 10.1.1.2 0 0 200? *> 10.3.1.1/32 10.1.1.2 0 0 200?
# View routing information accepted by Device A.
[~DeviceA] display bgp routing-table peer 10.1.1.2 received-routes BGP Local router ID is 1.1.1.1 Status codes: * - valid, > - best, d - damped, x - best external, a - add path, h - history, i - internal, s - suppressed, S - Stale Origin : i - IGP, e - EGP, ? - incomplete RPKI validation codes: V - valid, I - invalid, N - not-found Total Number of Routes: 2 Network NextHop MED LocPrf PrefVal Path/Ogn *> 10.3.1.0/30 10.1.1.2 0 0 200? *> 10.3.1.1/32 10.1.1.2 0 0 200?
After BGP ORF is enabled, Device C sends only two routes based on the prefix-based import policy provided by Device A, and Device A accepts only the two routes.
Configuration Files
DeviceA configuration file
# sysname DeviceA # interface GigabitEthernet0/1/8 ip address 10.2.1.2 255.255.255.252 # interface GigabitEthernet0/1/0 ip address 10.1.1.1 255.255.255.252 # interface LoopBack1 ip address 1.1.1.1 255.255.255.255 # bgp 100 router-id 1.1.1.1 peer 10.1.1.2 as-number 200 peer 10.2.1.1 as-number 100 # ipv4-family unicast undo synchronization import-route direct peer 10.1.1.2 enable peer 10.1.1.2 ip-prefix 1 import peer 10.1.1.2 capability-advertise orf ip-prefix both peer 10.2.1.1 enable # ip ip-prefix 1 index 10 permit 10.3.1.0 24 greater-equal 24 less-equal 32 # return
DeviceB configuration file
# sysname DeviceB # interface GigabitEthernet0/1/0 ip address 10.2.1.1 255.255.255.252 # interface LoopBack1 ip address 2.2.2.2 255.255.255.255 # bgp 100 router-id 2.2.2.2 peer 10.2.1.2 as-number 100 # ipv4-family unicast undo synchronization peer 10.2.1.2 enable # return
DeviceC configuration file
# sysname DeviceC # interface GigabitEthernet0/1/8 ip address 10.3.1.2 255.255.255.252 # interface GigabitEthernet0/1/0 ip address 10.1.1.2 255.255.255.252 # interface GigabitEthernet0/1/16 ip address 10.4.1.2 255.255.255.252 # interface LoopBack1 ip address 3.3.3.3 255.255.255.255 # bgp 200 router-id 3.3.3.3 peer 10.1.1.1 as-number 100 peer 10.3.1.1 as-number 200 peer 10.4.1.1 as-number 200 # ipv4-family unicast undo synchronization import-route direct peer 10.1.1.1 enable peer 10.1.1.1 capability-advertise orf ip-prefix both peer 10.3.1.1 enable peer 10.4.1.1 enable # return
DeviceD configuration file
# sysname DeviceD # interface GigabitEthernet0/1/0 ip address 10.3.1.1 255.255.255.252 # interface LoopBack1 ip address 4.4.4.4 255.255.255.255 # bgp 200 router-id 4.4.4.4 peer 10.3.1.2 as-number 200 # ipv4-family unicast undo synchronization peer 10.3.1.2 enable # return
DeviceE configuration file
# sysname DeviceE # interface GigabitEthernet0/1/1 ip address 10.4.1.1 255.255.255.252 # interface LoopBack1 ip address 5.5.5.5 255.255.255.255 # bgp 200 router-id 5.5.5.5 peer 10.4.1.2 as-number 200 # ipv4-family unicast undo synchronization peer 10.4.1.2 enable # return